My powered subwoofer outputs a loud bass sound when I turn it on. No signal cable connected, only a power source. When I connect a signal cable it does the same thing OR it actually outputs something decent, BUT way too loud still.
It's under warranty, but since I bought it abroad I want to make sure it is the amplifier so that when they send me a new one it'll work again. I have to pay for the shipping, which will be like $50, so want to make sure.